Measured-service telephone system



Jan. 21, 1930. A. TIMME 1,744,593

MEASURED SERVICE TELEPHONE SYSTEM Filed March 1929 HdaZbiFT Timms' Patented Jan. 21, 1930 UNITE ADALBERT TIMIIIE, OF RODEE, ITALY, ASSIGNOR TO SIETvIENS & HALSKE AKTIENGESELL- SGI'IAFT, WERNERWERK, 01E SIEMENSTADT, NEAR BERLIN, GERMANY MEASURED-SERVICE TELEPHONE SYSTEM Application filed March 7, 1929, Serial No. 345,008, and in Germany February 23, 1928.

The invention relates to a circuit arrange ment for automatic telephone instruments provided with self-charging devices, the instruments being arranged for both incoming and outgoing calls, and the invention relates more particularly to means for blocking the speaking circuit.

According to the invention, the blocking of the speaking circuit is effected by a relay which is located at the telephone instrument and is controlled by the impulse sender. According to the invention the relay comprises a differential relay, both windings or" which are so inserted in the speaking circuit that the relay is not afiected by incoming calls so that the speaking circuit is not blocked in that case. But in the case of outgoing calls, on operating the impulse sender or dial, one winding of the differential relay is short circuited by means of a contact device operated by the impulse sender and thus the microphone is blocked until a self-charging device, consisting of a meter, coin box, or the like, has been actuated.

By way of example, there is shown and described a circuit arrangement for an automatic telephone instrument in which a coin has to be inserted in order to set up a connection, while incoming calls can be received without having to pay a coin. The telephone instrument comprises the usual ringer WV bridged across trunk line conductors a and Z) in series with condenser C, switch hook H, microphone or transmitter M, receiver T, and impulsing contacts i. The impulsing contacts are controlled by the calling device as are the oil-normal contact N. In addition to the above elements there is a coin controlled spring or lever M, and a difierentially wound relay T -V which cooperate to short circuitthe microphone M. The two windings o1 the relay V oppose each other and are normally connected in series in line conductor 6.

The method of operating the apparatus will now be further explained with reference to the drawing, Fig. 1, which shows by means of the usual circuit diagram, an automatic telephone instrument in which the invention is embodied.

A connection is set up in the known manner by operating the impulse sender or dial. On rotating the number dial forward for the first time, the contact N is switched over by means of an arm or cam fitted on the dial shaft, andthereby the winding V of the differential relayV is short circuited. Therefore, the differential relay is now operated by its winding V which is now energized. Its contacts 12 and 41 are now switched over, thus keeping the winding V short circuited and blocking the microphone M. Hence, conversation withthe called subscriber can take place only after the speaking circuit has been opened. For that purpose is-provided a coin contact m, which is opened when a coin is inserted, thus removing the blocking of the microphone.

The instrument is ready for use for incoming calls without payment of a coin, because the number dial is then not operated so that its contact N, which causes the winding V to be short circuited, remains in the normal position and thus the difierentialrelay is not operated. Therefore, the microphone circuit is not blocked.

Obviously, the invention is not limited to the example shown. The coin boX can, of course, be replaced by some other self-charging device, for example a meter, without at tecting the invention.

That is claimed is: p

1. In a telephone instrument equipped with a self-charging device, a calling device, a relay tor rendering the talking circuit of the telephone inoperative, and contacts on said calling device for controlling the operation of said relay.

2. In a telephone instrument equipped with a self-charging device, a calling device, adifferential relay connected in one of the speak- 3 .L ,L i l .1 p I 03. L119 telephone, anu ll sponsive to the operation of sait cag vice for operating" said relay to render the talking circuit of tne telephone ineiiective.

In an automatic telephone instrument equipped with a self-charging device, a ditierential relay connected in the line terminating in the telephone but inoperative on calls incoming to the telephone, and means responsive to the initiation of a call from the telephone for 'cpei ating said relay to render the talking circuit of the telephone inoperative.

Ina telephoneinstrument equipped with a self-charging device, a calling device, a differential relay in the talking circuit of the telephone for rendering the talking cir'ciiit inoperative, and contacts on said calling device for short circiiiting a winding of said relay to operate said relay.

5. In a telephone instrument equipped with a self-charging device, a calling device, a relay controlled by the calling device for disabling the talking circuit of the telephone, and contacts controlled by the self-charging device for rendering the talking circuit operative.

6. In a telephone instrument equipped with a self-charging device, a calling device, a relay actuated responsive to the operation of the calling device for rendering the talking circuit of the telephone inoperative, and co'n tacts controlled by the selfcharging device for restoring the operative condition of the talking circuit. p

7. In a telephone instrument equipped with a coin collecting device, a calling device, a re: lay actuated responsive tothe operation of thecalling device for rendering the circuit of the telephone inoperative, and contacts 013- erated responsive to the insertion coin in the collecting device for restoring the epera tive condition of the talking circuit.

8. In a telephone instrument equipped with a self-charging device, a differential iel'a'yin the talking circuit of the telephone normally inoperative on calls incoming to the tele phone, means responsive to the initiation of a call from the telephone for operating said relay to render the talking circuit inoperative, and means controlled by the self-charging device for restoring the operative condition of the talking circuit.

9. In a telephone instrument equipped with a coin collecting device, a differential relay in the talking circuit of the telephonenormallv inoperative on calls incoming tothe telephone, means responsive to the initiation ofa call from the telephone for actuating said relay to render t ne talking circuit inoperative. and means controlled by the insertion of a eoin in said collecting device for restoring the operative condition of the talkingi circuit.

10. In a telephone instrument, a relay haviii'g two opposing windings connected in 1n the talking circuit of the telephone, means responsive to the initiation or" a call from the telephone for short circuiting one of said windings to operate the relay, means responsive to the operation of the relay for rendering the talking circuit inoperative, and means for restoring the operative condition of the talking circuit.

In witness whereof, I hereunto subscribe my name this 30th day of January, A. D. 1929.

ADALBERT TIMME.

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